getContentSetRootsContaining

It is significant that this method does not take a
Context, Project, or
Workspace as a parameter. The only case where
callers should ever need to use this method is precisely when they don't
know the context for the URL. If a caller knows the context, they
should already know where to find the URL. Specifically, in cases where
the caller knows what Project the URL is part of, they should
use the getContentSetRootsContaining(Project,URL) method
instead.

The only legitimate use of this method is in cases where the URL has come
from a source outside of the IDE. For example, a source control system or
file system might delvier an event about a file. In such cases, since the
event originated outside the IDE, there is no IDE context associated with
it. The only choice in that case is to call this method to find the
appropriate context(s).

Parameters:

url - the URL

Returns:

the content set roots containing the URL, or an empty collection
if no content set roots contain the file